<p>I don’t. I have one of those where I have a half brother and half sister whom I’ve only met a few times in my life. They are nice people, and fully self-sufficient and productive members of society, but I wouldn’t feel any obligation to care for them if they fell into bad straits. They’re not “family”; they’re strangers with whom I happen to share a biological relationship. I imagine it’s the same thing for these situations you’re referring to.</p>